Due to the increasing average size of rotors installed in wind turbines, and the need to limit the loads produced by the wind while guaranteeing the maximum possible power performance, variable speed and blade pitch control technologies have expanded. The wind turbines function by maximising their aerodynamic performance in a low winds regime. A variable rotational speed of the rotor may limit a wind turbine's rotational speed by modulating the torque in a power generator in a determined medium winds regime and, at high winds, restrict the rotor's rotational speed against gusts.
In the high winds regime, when the wind turbine produces the nominal power and the blade pitch angle limits the speed, a set of protective actions are established. The actions usually comprise shutting down operation. This may comprise a disconnection of the wind turbine and taking the blades to the feathered position when a certain rotational speed of the rotor is exceeded or when certain wind values above certain thresholds are detected, among other circumstances. Nonetheless, although these manoeuvres may protect the wind turbine in severe weather conditions, they may also subject it to fatigue.